I grew up on 'Speed Racer' and- -
I remember 'Speed Racer'.
- You remember 'Speed Racer'?
{Singing together) "Here he comes,
here comes 'Speed Racer,'
He's a demon on wheels."
(Laugh)
(Singing)
- Okay.
- This is real right?
I haven't dreamt this,
that you two are singing to each other?
(Laugh)
(Music)
- This show is all about the tweets that
you have put out on Twitter, about NASCAR.
- That was a few years ago.
If you dug these tweets out,
they would have been from 2014.
During the run, the weekly airings
of 'Cosmos' on Sunday night,
in prime time, on FOX, exactly.
All right, and then we learned that of
the 13 week run, one of those nights was
going to get bumped for NASCAR.
And I said, "What! you're going to put
NASCAR in for 'Cosmos', excuse me?"
So I said, "All right,
I am going to fight fire with fire."
Okay?
And I said,
"For all those who wanted to see 'Cosmos,'
but now are watching NASCAR, I'm going to
tweet the physics of NASCAR."
And this way, I'm respecting
that it's Memorial Day weekend,
you gotta do the NASCAR thing.
Sunday night, family, everybody's home,
NASCAR has a huge following.
But I'm going to be pumping this stuff
with some physics.
And that's what I did.
- I don't know why they just didn't have
you on 'Cosmos' but put a bunch
of branding stickers all over you.
(Laugh) - Just let you do 'Cosmos,'
like Pennzoil here.
- And let him run around the track. - Yeah.
- In overalls
with a whole lot of branding.
- That would be the collision
of NASCAR and astrophysics.
- That's very cool.
All right, so if we can bring up our first
tweet, we'll see what it says.
- Rubber tires on asphalt grant a maximum
speed of about 165 miles per hour
in the 24-degree banked turns
at Charlotte Motor Speedway.
- If you go faster than that,
you're not going to stay connected to
the road, and you hit the embankment.
- That's driver intelligence, that's
driver knowledge of each particular track.
- Well, it's presumed someone
would tell them this, yes.
(Crosstalk)
- Like the guy who did
175 miles per hour.
I'm sure he told them,
maximum speed is 165.
(Laugh) - Because, right,
because as his car was flung off the bank
and out of the arena.
- Of course, you could do 200, 190,
180 going into it,
because you're slowing down.
At that point,
you just don't want that to happen.
And who was it, was it Mario Andretti,
who said, "If you're in complete
control of your car,
you're not in the race."
- Wow.
- So I've heard this.
So they might be trying 166,
you're testing those limits of physics.
Otherwise, you're not in the race.
You don't want to do it safe.
(Crosstalk)
- They have to drive
in the red zone all the time.
- All the time, yeah, yeah.
In order to do that calculation,
you have to know the angle of the bank.
And it turns out, within some tracks,
the banks are not the same.
The bank angle's not the same
on different turns.
And it's not the same from track to track.
At Charlotte Motor Speedway,
the angle of the track is 24 degrees.
- How do I use that?
So as a race driver,
how am I going to use that banking to
my advantage over my opponent?
- So Gary, let's think about the 24 degrees,
but let's start at 0 degrees.
So here's a track that has no bank at all.
Okay, you can imagine that, sure,
okay, no bank.
If there was no friction between your
tires and the road and you try to go into
a turn, you just keep going straight.
You're not going to turn because you're
not connected to the road.
So you're in a straight line and
you will continue in a straight line
unless acted on by an outside force.
One of Newton's laws of motion.
If you bank the track, what'll happen is
the track now turns you, okay?
The track can actually engage a turn,
even with no coefficient of friction at all,
Okay?
So now put in friction, and
now you've got grip.
So you can just take that turn, just,
just, feel that turn.
And you know it and you feel it.
So there's one speed, one speed that will
maximize how fast you can go, depending
on the friction between your tires and
the road, and the angle and, sorry,
the radius of curvature.
Because if it's banked, but
it's like really wide,,
That's not a thing.
So you have to measure the radius
of curvature.
That's why I had to specify the banked
turns at Charlotte Motor Speedway.
So there's one speed and
it's 165 miles an hour.
At a coefficient of friction of one.
Generally asphalt and rubber comes
in about a coefficient of friction of one.
Okay, that's really good.
That's why tires
work very well on roads, that's why.
It's not an accident.
So you have to ask the question.
What is the fastest you can accelerate
from 0 to 60?
- Yeah. - It is not infinite.
It's just not, okay?
It depends on your
coefficient of friction.
At a coefficient of friction of one,
the fastest you can accelerate is
the acceleration of gravity itself.
- Really? - Which is fixed.
- Which is fixed, exactly.
That is the fastest you can accelerate.
And so in other words, if you drop a ball,
you look at how quickly it gains speed.
And then you have a car with a really
powerful engine, once it accelerates fast,
it goes this way.
So they'll go exactly the same speed.
Okay, this is an interesting fact about
coefficient of friction and acceleration.
You can accelerate faster,
if it has a rocket coming out of the back.
But then the ground is irrelevant.
- Yeah, exactly, yeah.
- You're just pushing it regardless-
- You've taken away the element of
coefficient of friction, right?
- You take away the tire/road connection.
- It's just being pushed.
It's not accelerating.
- Exactly, or if it is on a track where
you have intersecting teeth on a gear,
then you could just rotate that
as fast as you want.
- Which is what they do on
an aircraft carrier.
- Aircraft carrier! Yes.
- Yeah, you can do all kinds of stuff
on an aircraft carrier to get planes to
take off faster or slow down faster, okay?
So I did that calculation for
Charlotte Motor Speedway.
It was 165 miles an hour.
Then you watch them in the race.
There they are,
hitting above 200 in the straightaways,
then they go to the turn.
And at the peak turn
they're 165 miles per hour, every time.
- All right, Chuck,
let's get to another tweet.
We're going to stick with
the Charlotte Motor Speedway.
- Charlotte Motor Speedway,
which clearly you were watching this
when you were tweeting.
- "If the Charlotte Motor Speedway
increased their banking angle from
24 degrees to 31 degrees,
the earth as we know it would stop its
rotation." - It didn't say that.
(Laugh) It didn't say that.
It didn't say that. It says,
"If they increase their banking angle from
24 to 31 degrees, the cars could do
the turn at 200 miles per hour."
So this must be what you were
talking about.
The bank is turning the car itself.
- Exactly. - So the deeper the bank,
the higher the speed can be because you're
getting the force that's pressing the car
against the bank.
- There's more of a force to
enable that turn.
It's not just the sliding
of tires against the road sideways
that's trying to prevent you from sliding,
okay, that would then enable the turn.
It's... The bank is
empowering your car to go at a higher
speed in order to make that turn.
- See, that would be interesting from
a racing point of view because it means I
could hit the straightaway at 200 and
not lose energy through braking
coming into the bend.
- Not only that, not only that,
if you drive at the exact speed that
the bank was calculated for, you never
have to turn your steering wheel.
- It's a self-drive!
- The car thinks it's going in a straight line.
- The car thinks it's going in a straight line!
- So you're just surfing.
- So what's interesting to me
is if you know this about the turns,
the only steering you're doing
is to maneuver in front and
behind cars to position yourself.
So there's a whole other jockeying
of what's going on among the cars, and
it's not, 'I gotta turn left.'
And that was the joke in Charlotte,
the town, all right?
They say in Charlotte,
people only know how to turn left, okay?
- Right, yes, yes, yes.
- That's the joke, because
all the tracks go counterclockwise around.
And I'm saying, "If they're hitting the
turns at the exact speed, they're not even
turning the wheel to do that."
- How brave is the driver
that goes into the turn and goes,
"Nah, I'll let the car take control of this."
(Laugh) - Whoa, not a chance.
So how much of a change in angle on
the banking could we get away with, and
what sort of speeds could we play with?
- Well, my general question would be, you
want more action, you want more speeds?
Why not just increase the angle?
Here's the problem.
If you're not doing 200 miles an hour,
the car's going to want to slide down, yeah.
- Slide down, right.
- You don't have enough force pinning it
against the bank.
- Yeah, so if something goes down
going into the turn and
you don't keep up that speed, yeah,
the car's not stable.
- Is it possible to get to a speed
where you not only can go up, but
total 'Hot Wheels' corkscrew?
(Laugh)
Okay, it's like you go into the turn,
you're up on the bank, and then
all of a sudden corkscrew through and
you come out the other side.
- Yeah, the answer is yes.
- Really? - Yeah, in fact
they do it in amusement parks.
So in other words,
let me restate your comment.
If you travel fast enough, then...
So now you're going up, right, because
to do a corkscrew you have to go up.
So if you're traveling fast enough, you
can get yourself enough upward momentum so
that your car continues to press against a
surface that is pointing downwards, okay?
And then you come down off of that and
do it another time,
yeah, in principle you can design
a racetrack where cars do corkscrews.
But you have to be careful,
because you don't want the car to stall
before you go into it.
- Yes! - Then you fall out.
- Oh, that's amazing!
(Laugh) - Oh my God, you're making me such
a NASCAR fan right now.
Corkscrews and cars falling from the sky.
- Well, yeah, if you don't hit the speed.
It's all about the speed that you
got to hit.
And so, yeah,
it's a whole other danger factor.
- That's awesome.
- It ain't even about to crash,
is your car going to fall out of the sky?
- Will it fall out of the sky.
- Right.
- See, this is why I don't watch NASCAR,
because I grew up on 'Speed Racer' and-
- I remember 'Speed Racer'.
- You remember 'Speed Racer'?
(Singing together) "Here he comes,
Here comes 'Speed Racer,'
He's a demon on wheels."
(Laugh)
(Singing)
- Okay.
- This is real, right?
I haven't dreamt this,
that you two are singing to each other?
(Laugh) - The power of pop culture on
childhood.
- On childhood,
it's childhood pop culture.
- Wait a minute, are you a fan of NASCAR?
Have you ever followed NASCAR?
I've visited,
I've been at one NASCAR race in my life.
- Yeah, all right.
- I never understood why there was so
much more interest in NASCAR
relative to Formula One,
at least in the United States.
I just didn't understand that.
Did they have better marketing?
Because the Formula One cars are pretty
cool looking, right?
- They're like rockets with wheels.
- Yeah. - And the fact that they're so
low to the ground. - They're like that.
- They're this far off the ground.
- So I've never understood
the difference in appeal.
But I like high performance people.
I like high-performance machines,
just as a general thing.
- I'll tell you why Formula One is not as
popular here in America as NASCAR:
(French accent) Because the Formula One racers
(French accent) speak like this.
(Laugh)
(Southern accent) And NASCAR drivers talk
(Southern accent) this like this, damn it!
That's America!
- 'Murica', okay.
- As the token European,
I feel I should stand up.
But I just think I'm going to get
knocked back down again.
- No, it's nothing against you.
- No, I know it's not against me.
But anyway, it's interesting.
One's an oval and you couldn't put
a NASCAR race in Monte Carlo.
- But you can with a Formula One,
which is so, so special.
Anyway, next tweet, let's go there.
- All right, "Spoilers increase
the effective weight (traction) over a car's
rear wheels at high speed without
increasing the car's mass." - Yeah, yeah.
- Okay.
- Have you noticed, either in cars you've
driven or observing a police car,
that if you have a heavy trunk,
your car is more stable on the road.
I don't know if you have ever
noticed this.
- I transport a lot of bodies in my trunk.
- Okay, so you should know.
- So I'm very well aware.
- So you would know, and...
Back in the day, when you had
rear wheel traction,
if you had higher weight over those wheels,
then in occasions where you might
have spun out, you don't.
- You don't.
- And anytime your car is spinning,
then you don't have full traction with
the ground and you're not in complete
control of your car.
- It's like sledding.
- I don't sled.
- Well, drifting. - You don't sled?
Here's the deal, in sledding you need
a fat kid on your sled team.
(Laugh)
If you don't have a fat kid on your sled
team, forget it.
- It gives you more traction.
- Right, it's just what you were saying.
- You didn't get that email
about political correctness?
(Laugh) - I didn't know this, about, okay, okay.
(Laugh) - So go ahead.
- So the point is if you're spinning,
increase the weight, and
then the contact with the ground becomes...
The integrity gets restored and
your traction is returned.
- The trouble is, with putting a whole
load of bricks in the back of your NASCAR,
you're going to lose everything
because it's weight.
- Exactly, so...
Your weight is whatever
a scale will show.
- Let's not talk about that.
(Laugh)
- I've been eating donuts lately,
I'm just saying.
Mexican, a lot of Mexican.
Let's not talk about the scales.
- You could put bricks in the trunk of
every NASCAR to increase that traction.
You could do that, but
then the engine---the motor--
has to accelerate more weight.
And Newton's second law of motion, the
force equals the mass times acceleration.
If the mass goes up, then you're getting
a lower acceleration from the force.
You're not going to go as fast, okay?
- Yeah. - Or you're not
going to be as nimble.
- So is there any way to increase
the weight on the back wheels,
or the weight of the car,
without increasing the mass of the car?
And there is.
That's what the spoiler does.
So as you're driving,
air comes across the spoiler,
presses down,
increases the weight of the car,
without increasing the mass of the car.
And this greatly improves your traction,
especially at high speeds.
- It's making that airflow over the rear
wheels push that weight down.
Therefore, you don't increase the mass
of the vehicle,
but you are increasing the down force.
Is that right?
- Right, so there are other factors in
the shape of the vessel regarding
the aerodynamics.
What you don't want is to have turbulence
in the back of your car,
which then creates a drag, a suction.
It's kind of a backwards drag.
This is why drafting works, okay?
So you have a car that would have
turbulence in the back,
you come up behind it,
okay, now it works in two ways.
One, the car that's leading moves
faster because it doesn't have
the drag behind it.
So people say, "Stop drafting off of me,
I'm towing you."
You're not actually towing the car.
- Right.
- No, no, no, you want the person there.
- Right, so they're- -
You actually want to be
the second car rather than the first car.
But if you are the first car, it's better
to have someone drafting than not.
That's all I'm saying.
- Because that drafter is
eliminating their drag.
- The drafter is eliminating the lead
car's drag, correct.
So now the air comes back and
they have someone else drafting that and
someone else drafting that.
Now you are sucked in behind it.
So this affects fuel efficiency too, okay?
I did this experiment once.
So when I first got a car that tracked
your instantaneous... - Fuel consumption.
- Fuel consumption, miles per gallon.
- Right. - And you notice if you
take your foot off the pedal, the miles per
gallon goes up because you're moving but
you're not sucking gas.
So I'm just doing my physics experiments
on the road.
My first outing in a car that did this.
- Okay. - You know, you might have a problem.
- (Laugh) No! So watch, so I do this.
And I say, "I wonder what'll happen
if I get behind this truck?".
So I'm driving, and
I'm getting 25 miles a gallon, and
then I slide in behind the truck, and
my foot is still on the accelerator, okay?
And whoa, it was like 80 miles a gallon.
I was behind the truck.
- Because you're drafting the truck.
- I'm drafting the truck and
it was like 'whoa!'
- And Neil drove all the way to Florida
and he was only going to the store for
some bread.
(Laugh)